If you walk into any traditional martial arts school, you'll see people doing kata. Kata are choreographed sequences comprised of methodical footwork, powerful blocks, and precise strikes. All techniques are performed against an imaginary opponent.
Stepping into a modern school, which often describe their curriculums as "fighting systems", "tactical martial arts", or "combatives", you will see nothing of the sort: instead, you'll watch students drilling, sparring, doing bagwork. Talk to the practitioners of these systems and they'll tell you that kata are a waste of time.
"Kata are choreography," they might tell you. "They don't teach you how to fight."
These are fairly popular opinions, but they aren't limited to folks training Krav. An increasing number of non-traditional Karate and Taekwon Do institutions minimize time spent on kata or skip them entirely. And the arguments are largely factually correct: you can't become a good fighter by training kata alone, and the majority of professional fighters got where they are without knowing any kata at all.
It is much quicker to learn how to throw punches and kicks by doing bag work and shadowboxing.
It is much more effective to build cardio and strength on gym equipment.
It is much more reliable to learn how to win a fistfight by spending time in a boxing ring.
But, no matter how accurate, these answers are incomplete. Crucially, none of them are the sole objective of a traditional martial artist.
Most traditional martial artists want to be able to handle themselves in a fight. (I sure do.) But if you're training a TMA instead of a modern combat system, it's likely there are other things you're looking for as well. Things like being immersed in a tradition, experiencing Karate culture, collaborating with and testing yourself against a group of like-minded peers. I'm a computer programmer, and pretty laid back to boot: if I spent eight hours a week training solely for combat effectiveness, it wouldn't be a rewarding use of my time.
One of the kata I perform, tsuken akachu no ieku de, is over 600 years old. It has been passed down from teacher to student for more than 25 generations, and I can't help but remember that with a sense of awe, every time I perform it. Each technique that I drive myself to perfect has been the work of martial artists beyond number, each struggling, each slowly approaching a perfect expression of the form. And incredibly, across oceans, languages, and centuries, it is my turn to make the kata part of myself. Someday, it will be my turn to pass it on again.
And there are martial applications to kata: figuring out how the sequences apply in real-world situations is a big part of the mental aspect of Karate.
I hope to avoid needing to use these skills to defend myself, and so far I have been successful. But the enjoyment, the connection to the past in our kata, I experience every day of my life. Only part of training Karate is done for self defense: a lot of training Karate is in order to be better at Karate. And that's okay.